A retired knight who raises Arthur as his foster son.
The correct answer is A. lunches and river.
A common noun is concrete - it refers to something you can touch, feel, something that surrounds you; words such as desk, mirror, rug, are all common nouns.
B is incorrect because those are proper nouns, meaning they refer to the names of people or places. C is incorrect because eat is a verb, and side is an abstract noun. D is incorrect because both words are verbs.
The answer is magazines because I'm pretty sure that it means something that is printed.
What are you reading? And what part of the reading?